Tube Temperature

[TremoJem]

I used to run a fan underneath my tubes to keep the mother board and all other components from heating up in my Tremoverb 2x12 Combo.

The fan was clipped to the panel that protects the two speakers and faced upwards to circulate cool air to the tubes and keep the area from heating up.

What if any information should I know about the real effects of keeping tubes cool or letting them get hot. I started to think that maybe temperature contributes to tone and combos have been designed this way for ever so why should I add cooling.

Thanks for your insight.

 

[EtherealWidow]

Wouldn't really worry about it. Temperature doesn't really contribute to the tone. Due to the way some people talk some people think that the hotter the tubes are, the more distortion you get. If that were true, triple recs in Alaska would all be sparkly clean. The fan couldn't hurt though.

 

[Thatguy]

Ha ha ha! So you are saying that i should go to Alaska to record all of my clean tracks! I bet death metal sounds sweet in in the desert. Oh wait remember that November Rain video... That must be why slash played his solo out in the middle of the desert. Ha.

 

[thelastleroy]

Keep the fan. Heat will eventually kill something in your amp, especially being a combo (tubes hang down, heat goes up into the chassis). Just had $200 worth of overheated components replaced on my Nomad head. The tech recommended installing a fan, which I did.

If you're really concerned, you can even buy specially made heat-sink sleeves for your tubes. They're supposed to increase tube life and reduce microphonic noise, pricey though...

http://www.partsconnexion.com/tube_cool_pearl.html

 

[TremoJem]

Thanks for all the great replies.

 

[94Tremoverb]

I was discussing this with someone else on another forum, and ended up taking proper temperature readings of my Tremoverb. Conclusions...

1 - I do think temperature contributes to tone - but it's not how hot the tubes get that matters, it's how hot the amp (possibly mainly the transformers) gets.

2 - the Tremoverb gets dangerously hot inside the chassis if you leave it on fully (not on standby) for more than two hours. If you put it on standby, it cools down a bit but not that much, which then reduces the time to about an hour (after one hour of standby) before it reaches dangerous levels again when you turn back on fully.

3 - it's definitely going to be worse with the combo version. A large portion of the heat comes from the tubes going upwards onto the chassis. The PT does contribute some, and the circuitry inside the amp a little, and the OT some but only when fully on (not on standby), but the tubes are the bulk.

By dangerous I mean up to or above the 85ºC/185ºF rating on electrolytic caps. While this isn't a hard and fast upper limit, running that hot really isn't good for them and possibly some other parts... eg LDRs. Ever wondered why the Tremoverb seems to suffer more LDR failures than other Mesas which use large numbers of them, such as the standard Dual Recto or the MkIV? I think I know now.

Keep the fan, if you don't mind the noise (if it's audible). I don't particularly like them unless they're absolutely essential, so I don't think I'm going to fit one, but the experiment did make me much more aware of how hot it gets and to be more inclined to turn it right off than put it on standby, for shorter 'unused' periods than I did before.

 

[TremoJem]

Great information from "94Tremover". I can't thank you enough for the time and effort you put into this discussion.

I will keep the fans!

Luckily they are industrial in design and I expect long life out of them. They truly do a great job.

I used to put my hand to the top of the combos and feel an amazing level of heat coming off the combos. This concerned me.

I implemented the fans and problem solved.

Audible sound is not a problem, and I anticipate recording will not be effected by them either.

Thanks again.

 

[J.J]

Late to the party I know :lol:

At least a few of bigger the new Mesa's run fans, the Lonstar and MkV both do. My ED even has a fan output marked on the main board, but Mesa decided not to add a fan for some reason. If Mesa are adding fans from factory they must be needed, I just don't understand why some get fans and some don't.

I run my amp for long periods and the front panel and top grill would be to hot to touch after a few hours so I added a pair of low noise fans above the power tubes to pull the heat out. The fans can't be heard when playing even at very low volume and the amp runs much cooler. Electronics can generally take a lot heat, but besides the tubes, if a component is much hotter than I can stand to touch, I don't like it.

I have an Express 5:25 which I don't believe runs hot enough to bother with fans.

 

[TremoJem]

That is interesting...pulling the heat out. I might take a look at that solution too.

I have an open back combo so I am introducing fresh air by drawing it in, then I push it upwards and directly on the tubes.

Thanks again everyone.

 

[Tuna141]

By dangerous I mean up to or above the 85ºC/185ºF rating on electrolytic caps. While this isn't a hard and fast upper limit, running that hot really isn't good for them and possibly some other parts...

+1.

The life of most electrical components is reduced the higher the temperature they are exposed to. Electrolytic caps are especially sensitive to high temperatures since it dries out the electrolyte. The generally accepted rule of thumb is that every 10deg C over their usual 85C will cut the life expectancy of a capacitor in half.

It is definitely worthwhile to keep your amp running cool.

 

[Thatguy]

So you want to keep a cool head

 

[TremoJem]

Absolutely

A cool head assures a long life...I think?